IGF2 Promotes Activation of Estrogen Receptors in Basal-Like Breast Cancer Cells Angelique Richardson Loma Linda University
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Loma Linda University TheScholarsRepository@LLU: Digital Archive of Research, Scholarship & Creative Works Loma Linda University Electronic Theses, Dissertations & Projects 3-1-2011 IGF2 Promotes Activation of Estrogen Receptors in Basal-like Breast Cancer Cells Angelique Richardson Loma Linda University Follow this and additional works at: http://scholarsrepository.llu.edu/etd Part of the Medical Genetics Commons, and the Medical Microbiology Commons Recommended Citation Richardson, Angelique, "IGF2 Promotes Activation of Estrogen Receptors in Basal-like Breast Cancer Cells" (2011). Loma Linda University Electronic Theses, Dissertations & Projects. 60. http://scholarsrepository.llu.edu/etd/60 This Dissertation is brought to you for free and open access by TheScholarsRepository@LLU: Digital Archive of Research, Scholarship & Creative Works. It has been accepted for inclusion in Loma Linda University Electronic Theses, Dissertations & Projects by an authorized administrator of TheScholarsRepository@LLU: Digital Archive of Research, Scholarship & Creative Works. For more information, please contact [email protected]. LOMA LINDA UNIVERSITY School of Medicine in conjunction with the Faculty of Graduate Studies ____________________ IGF2 Promotes Activation of Estrogen Receptors in Basal-like Breast Cancer Cells by Angelique E. Richardson ____________________ A Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Microbiology and Molecular Genetics ____________________ March 2011 © 2011 Angelique E. Richardson All Rights Reserved Each person whose signature appears below certifies that this dissertation in his/her opinion is adequate, in scope and quality, as a dissertation for the degree Doctor of Philosophy. , Chairperson Daisy D. De León, Associate Professor of Physiology and Pharmacology Eileen Brantley, Assistant Professor of Basic Sciences and Pharmaceutical Sciences Carlos Casiano, Associate Professor of Biochemistry and Microbiology Subburaman Mohan, Research Professor of Medicine, Biochemistry and Physiology Padma Uppala, Associate Research Professor of Environmental and Occupational Health Nathan Wall, Assistant Professor of Basic Sciences and Pediatrics iii ACKNOWLEDGEMENTS It is my pleasure to show my gratitude to those who made the completion of this dissertation possible. I am indebted and heartily thankful to my Principal Investigator, Dr. Daisy De Leon, whose support and guidance lead me from my first experience with research in the Initiative for Maximizing Student Development (IMSD) program as a junior in college to near completion of the MD/PhD program at LLU. I would also like to thank Dr. Nalo Hamilton and Dr. Willie Davis for all of their proofreading and support in so many ways. I am also grateful to my dissertation committee members who made available their services and advice to me. I thank my parents Mr. Alvin Ellerbee I and Mrs. Audrey Ellerbee and siblings Alvina and Alvin Ellerbee II who have always been a great source of love and strength. Your prayers were invaluable. I owe my deepest gratitude to my husband, Henry Richardson, whose perpetual love and unwavering support have been a pillar of strength every step of the way. iv CONTENTS Approval Page .................................................................................................................... iii Acknowledgements ............................................................................................................ iv Table of Contents .................................................................................................................v List of Tables .................................................................................................................... vii List of Figures .................................................................................................................. viii List of Abbreviations ...........................................................................................................x Abstract .............................................................................................................................. xi Chapter 1. Introduction ............................................................................................................13 Disparities in Breast Cancer ............................................................................13 Role of IGF2 in Breast Cancer ........................................................................14 Insulin-like Growth Factor Family ..................................................................15 IGF2 ...........................................................................................................16 IGF1R ........................................................................................................17 IGF2R ........................................................................................................18 Insulin Receptor ........................................................................................19 Estrogen Receptors .........................................................................................20 Estrogen Receptor in Cancer ....................................................................20 Estrogen Receptor Signaling .....................................................................22 Growth Factor Receptor and Estrogen Receptor Cross-talk ............................23 Breast Cancer Subtypes ...................................................................................24 Significance of Studies ....................................................................................26 Approach of Studies .........................................................................................27 2. IGF2 Activates ER- and ER- via the IGF1R and IR in Basal-like Breast Cancer Cells ..........................................................................................................30 Abstract ............................................................................................................31 Introduction ......................................................................................................31 Materials and Methods .....................................................................................34 v Cell Culture ................................................................................................34 Quantitative Real Time PCR .....................................................................35 Subcellular Fractionation ...........................................................................36 Western Blot Analysis ...............................................................................36 siRNA Analysis .........................................................................................38 Statistical Analysis .....................................................................................38 Results ..............................................................................................................39 ER- and ER- mRNA in Breast Cancer cells ..........................................39 Phosphorylation and Subcellular Translocation of ER-α and ER-β ..........40 IGF-2 Stimulates the Translocation of the ERs through IGF-1R and IR .........................................................................................................44 Discussion ........................................................................................................51 Declaration of Interest......................................................................................55 References ........................................................................................................56 3. Extracellular Expression of ERs in Breast Cancer Tissues ..................................62 Introduction ......................................................................................................62 Materials and Methods .....................................................................................62 Breast Cancer Tissue Specimens ...............................................................62 Immunohistochemistry Analysis ...............................................................63 Results ..............................................................................................................64 Detection of ER-α and ER-β in Breast Cancer Tissues .............................64 Discussion ........................................................................................................65 4. Discussion ..............................................................................................................67 Conclusions and Future Directions ..................................................................67 References ..........................................................................................................................73 vi TABLES Tables Page 1. Typical Immunohistochemical Classification of Breast Cancer Subtypes ............25 vii FIGURES Figures Page 1. Bar Graph of Western Blot Analysis Showing IGF2 Expression in Normal and Malignant Breast Tissue Samples ...................................................................14 2. Schematic Representation of Pre-proIGF2, proIGF2 and mature IGF2 ................17 3. ER-α and ER-β mRNA expressed as fold change of mRNA expression in MCF-7, CRL-2335 and Hs578T cells ....................................................................39